Supersonic molecular beam injection (SMBI) can penetrate the separatrix of the HL-2A plasma and result in the increase of important plasma parameters, such as the plasma storage energy, the βp, the line averaged electron density, the central electron density and temperature. During deuterium plasma ECRH and deuterium SMBI, the neutron account rapidly increases along with the electron density and temperature increments. SMBI was considered as an alternate fuelling technique, which may provide a higher particle source at the pedestal top for ITER. A mean velocity for hydrogen SMBI of about 1.7km/s was detected in HL-2A torus and the measured result was compared with that for the effusion in vacuum.